ISEN 281 EXAM 2

Comparing with metals, plastic materials have ________ thermal conductivity.

(A) higher (B) lower

(B) lower

Which plastic materials are stronger and more rigid?

(A) Thermosets. (B) Thermoplastics.

(A) Thermosets.

Which plastic materials are more ductile?

(A) Thermosets. (B) Thermoplastics.

(B) Thermoplastics.

Which plastic materials are easier to recycle?

(A) Thermosets. (B) Thermoplastics.

(B) Thermoplastics.

hich one of the following shape-forming processes (for plastics) is the simplest?

(A) Casting (B) Injection molding

(C) Blow molding (D) Extrusion

(A) Casting

Which one of the following shape-forming processes (for plastics) is the most commonly used?

(A) Casting (B) Injection molding

(C) Blow molding (D) Extrusion

(B) Injection molding

Plastic casting processes can be used to produce parts from ________

(A) all plastics.

(B) thermoplastics only.

(C) thermosets only

(D) some thermoplastics and some thermosets.

(D) some thermoplastics and some thermosets.

Plastic injection molding processes are used primarily for ________

(A) Thermosets. (B) Thermoplastics.

(B) Thermoplastics.

Plastic blow molding processes are used for ________

(A) thermosetting materials. (B) thermoplastic materials.

(B) thermoplastic materials.

In plastic blow molding, the starting resin is usually in the form of ________

(A) pellets. (B) melted liquid.

(A) pellets.

Drilling is best described as __________

(A) single-point machining. (B) multi-point machining. (C) abrasive machining.

(B) multi-point machining.

In orthogonal cutting, the cutting edge is a straight line _________ to the relative velocity between tool and workpiece.

(A) perpendicular (B) parallel (C) at a certain angle

(A) perpendicular

Most cutting processes are __________

(A) three-dimensional. (B) orthogonal cutting.

A) three-dimensional.

As rake angle _______, the cutting edge (i.e. the cutting tool) becomes sharper.

(A) increases (B) decreases

(A) increases

As shear angle increases, chip thickness ________

(A) increases. (B) decreases.

(B) decreases.

For any given uncut chip thickness (depth of cut), a smaller shear angle means a ______ cutting force.

(A) higher (B) lower

(A) higher

When uncut chip thickness (depth of cut) increases, cutting force typically __________.

(A) increases (B) decreases

(A) increases

If rake angle increases, shear angle will _______.

(A) increases (B) decreases

(A) increases

If rake angle increases, cutting force will _______.

(A) increases (B) decreases

(B) decreases

If inclination angle increases, cutting force will _______. (What will happen to effective rake angle?

(A) increases (B) decreases

(B) decreases

increase

Generally speaking, __________ cutting force is desired in metal cutting.

(A) lower (B) higher

(A) lower

Generally speaking, as cutting speed increases, cutting force ____________________.

(A) increases (B) decreases (C) does not change much

(C) does not change much

When uncut chip thickness (depth of cut) increases, cutting force typically __________.

(A) increases (B) decreases (C) does not change much

(A) increases

Generally speaking, using coolant __________ cutting force slightly.

(A) reduces (B) increases

(A) reduces

Generally speaking, using coolant increases tool life __________.

(A) slightly (B) significantly

(B) significantly

Generally speaking, as hardness (of tool materials) increases, their toughness __________.

(A) increases (B) decreases

(B) decreases

Generally speaking, as cutting speed increases, tool life __________.

(A) increases (B) decreases (C) does not change much

(B) decreases

The desired qualities for an ideal tool material are: harder than workpiece; retain hardness at high temperature; resist

wear and thermal shock; impact resistant; and chemically inert. Which one of the following tool materials incorporates

all these qualities?

(A) Diamond. (B) Ceramics. (C) HSS.

(D) None of them. (E) All of them (A, B, and C).

(D) None of them.

Which deposition method has higher depositing temperature?

(A) CVD (Chemical Vapor Deposition). (B) PVD (Physical Vapor Deposition).

(A) CVD (Chemical Vapor Deposition).

A friend of yours has got a job as an applications engineer in a grinding wheel company. Your friend goes to customers’ sites to conduct grinding tests, demonstrating the high performance of their grinding wheels. The company has two types of superabrasive grinding wheels: diamond and CBN. Their customers mainly manufacture steel parts for

automobile industry. Your friend knows that you have taken ISEN 281 and comes to you for advice. Which type of superabrasive grinding wheels is more suitable for these customers?

(A) Diamond. (B) CBN

(B) CBN

If inclination angle increases, effective rake angle

_____.

(A) increases (B) decreases

(A) increases

If effective rake angle _______, the cutting tool

becomes sharper.

(A) increases (B) decreases

(A) increases

If the cutting tool becomes sharper, cutting force will

_______.

(A) increases (B) decreases

(B) decreases

If effective rake angle increases, the cutting force will ___

decrease

If inclination angle increases, cutting tool becomes ___

sharper

In a turning operation, if the initial diameter minus the final diameter equals 4 mm, what is the depth of cut?

(A) 1 mm. (B) 2 mm. (C) 4 mm.

(B) 2 mm.

In a turning operation, a decrease in cutting speed will ____________ MRR.

(A) increase (B) decrease

(B) decrease

Flank wear occurs on _______________

(A) the tool face that interacts with the newly-generated chip.

(B) the tool face that interacts with the newly-generated surface of workpiece

(B) the tool face that interacts with the newly-generated surface of workpiece

Generally speaking, a decrease in cutting speed will ____________ the tool life.

(A) increase (B) decrease

(A) increase

For a standard twist drill, the rake angle along the main cutting edges (lips) is _________

(A) different at different point. (B) the same everywhere.

(A) different at different point.

___________ is the process of machining INTERNAL cylindrical and conical surfaces; ________ is the

process of machining EXTERNAL cylindrical and conical surfaces.

(A) Turning/Boring (B) Boring/Turning

(B) Boring/Turning

hich one of the following orders represents the surface roughness order (from the roughest to the

smoothest) generated by these processes?

(A) Honing > Reaming > Drilling. (B) Reaming > Drilling > Honing.

(C) Drilling > Reaming > Honing. (D) Drilling > Honing > Reaming.

C) Drilling > Reaming > Honing.

(8-10) Holes are drilled in a part. It is found that the hole surface is too rough. You are asked to judge whether

the following ideas will improve the surface quality.

(8) Increase drill rotational speed. (A) Probably will. (B) Will not.

(9) Increase feedrate. (A) Probably will. (B) Will not.

(10) Use a reaming operation after drilling. (A) Probably will. (B) Will not.

(A) Probably will.

(B) Will not.

(A) Probably will.

In turning operation, if the tool tip is set higher than the rotation axis of workpiece (see the

figure), the effective rake angle will be ______ than that when the tool tip is set at the same

height as the rotation axis of workpiece.

(A) smaller. (B) larger.

(B) larger.

In a turning operation, if the tool tip is set higher than the rotation axis of workpiece (see the figure), the effective

clearance angle will be ______ than that when the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller. (B) larger.

(A) smaller.

In a turning operation, if the tool tip is set lower than the rotation axis of workpiece (see the figure), the effective

rake angle will be ______ than that when the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller. (B) larger.

(A) smaller.

In a turning operation, if the tool tip is set lower than the rotation axis of workpiece (see the figure), the effective

clearance angle will be ______ than that when the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller. (B) larger.

(B) larger.

In the equation to calculate the cutting speed in milling, v = πDN, D is the diameter of _____

(A) the workpiece. (B) the hole being machined. (C) the tool.

(C) the tool.

In _____ milling, the surface is generated by teeth located on the periphery (only).

(A) slab (B) face (C) end

(A) slab

In a milling operation, if the surface generated is perpendicular to the cutter rotation axis, it is called ________.

(A) slab milling (B) face milling

(B) face milling

Pockets can be machined by __________ milling.

(A) slab (B) face (C) end

(C) end

Up (conventional) milling and down (climb) milling refer to ___________

(A) slab milling only. (B) face milling only. (C) both slab and face milling.

(C) both slab and face milling.

A) Straight teeth. (B) Helical teeth.

(6) See the above figure. Cutters for slab milling may have straight or helical teeth. Which one result in oblique cutting action?

(A) (B)

(B) Helical teeth.

See the above figures.

(7) For either slab or face milling, surfaces can be generated by two distinctly different methods: up milling (conventional

milling) and down milling (climb milling). Which one is up milling? (A) (B)

(8) In which case the chip is thin at the beginning and thick at the end? (A) (B)

(9) In which case the surface scale does not affect tool life? (A) (B)

(10) In which case a higher clamping force is needed to hold the workpiece? (A) (B)

A

A

A

A

In a boring operation, if the tool tip is set higher than the rotation axis of workpiece (see the figure to right), the effective rake angle will be ______ than that when the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller (B) larger

(A) smaller

For the same situation as above, the effective clearance angle will be ______ than that when

the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller (B) larger

(B) larger

When machining very hard materials such as hardened metals and ceramics, grinding operation is _______ preferable

than turning and milling.

(A) more (B) less

(A) more

Grinding operation is widely used in the automotive industry; but has no applications in the semiconductor industry.

(A) True (B) False

(B) False

The surface roughness and accuracy produced by grinding is generally ________ that produced by turning or milling.

(A) up to 10 times better than (B) worse than (C) about the same as

(A) up to 10 times better than

Superabrasives include CBN and diamond. ______ wheels are used to grind ferrous metals; the other wheels are used

to grind non-ferrous metals and nonmetals.

(A) CBN (B) Diamond

(A) CBN

There are three major bond systems for grinding wheels: vitrified, organic, and metal. Which of the following

associations is true?

(A) Vitrified → glass; Organic → resin. (B) Vitrified →resin; Organic → glass

(A) Vitrified → glass; Organic → resin.

Grain size, bond type, and pore size of a grinding wheel affect the performance of the wheel. Which one of the

following is NOT true?

(A) Finer grain size produces rougher surface.

(B) The vitrified bond system is more rigid and more brittle than the resin bond system.

(C) Pore space determines whether the wheel has an “open” structure or “closed” structure.

(A) Finer grain size produces rougher surface.

The purpose of truing and dressing is to prepare the grinding wheel to have correct form, concentricity, and cutting

action. Which one of the following is NOT true?

(A) Truing/dressing is sometimes called balancing.

(B) Some abrasive grains are removed from the wheel during truing/dressing.

(C) Truing/dressing can be done by using a single-point diamond tool or a multi-point diamond tool.

(A) Truing/dressing is sometimes called balancing.

Four primary grinding types are cylindrical, internal, centerless, and surface grinding. Which one is true regarding

cylindrical grinding?

(A) Both wheel and workpiece rotate.

(B) The wheel rotates but the workpiece does not rotate.

(C) The workpiece rotates but the wheel does not rotate.

(A) Both wheel and workpiece rotate.

In creep feed grinding, _________________________ is much smaller.

(A) depth of cut

(B) feed rate

(C) required horsepower

(B) feed rate

For double disk grinding, both sides of _______________________ at the same time.

(A) the grinding wheel are grinding the workpieces

(B) the workpieces are being ground

(B) the workpieces are being ground

In a boring operation, if the tool tip is set lower than the rotation axis of workpiece (see the

figure to right), the effective rake angle will be ______ than that when the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller (B) larger

(B) larger

For the same situation as above, the effective clearance angle will be ______ than that when

the tool tip is set at the same height as the rotation axis of workpiece.

(A) smaller (B) larger

(A) smaller

LBM (Laser Beam Machining) and AWM (Abrasive Waterjet Machining) are primarily used to cut _________________ (choose one).

(A) flat sheets (B) cylindrical parts (C) hollow cavities

(A) flat sheets

In AWM (Abrasive Waterjet Machining), consumables _______ be used.

(A) will not (B) will

(B) will

Comparing to traditional machining processes (turning and milling, for examples), thermal cutting processes (such as oxygen fuel cutting and plasma arc cutting) will generate ____ accurate dimensions.

(A) more (B) less

(B) less

Generally speaking, which one of the following processes generates the most accurate dimensions?

(A) LBM (Laser Beam Machining) (B) Oxygen fuel cutting

(C) PAC (Plasma Arc Cutting) (D) AWM (Abrasive Waterjet Machining)

(A) LBM (Laser Beam Machining)

Generally speaking, which process generates more HAZ (Heat Affected Zone)?

(A) Oxygen fuel cutting. (B) PAC (Plasma Arc Cutting).

(C) AWM (Abrasive Waterjet Machining)

(A) Oxygen fuel cutting.

LBM (Laser Beam Machining) is used __________________.

(A) primarily for cutting small holes (B) primarily for cutting large holes

(C) for cutting both small and large holes

(C) for cutting both small and large holes

LBM (Laser Beam Machining) ______ generate cutting forces.

(A) does not (B) does

(A) does not

Which one of the following processes does not generate HAZ (Heat Affected Zone)?

(A) LBM (Laser Beam Machining) (B) Oxygen fuel cutting

(C) PAC (Plasma Arc Cutting) (D) AWM (Abrasive Waterjet Machining)

(D) AWM (Abrasive Waterjet Machining)

Which one of the following processes is like a “corrosion” process?

(A) Chemical machining. (B) Electrochemical machining.

(C) Abrasive flow machining. (D) Ultrasonic Machining.

(A) Chemical machining.

Which one of the following processes is the reverse of electroplating?

(A) Chemical machining. (B) Electrochemical machining.

(C) Abrasive flow machining. (D) Ultrasonic Machining.

(B) Electrochemical machining.

One of your friends works in a manufacturing plant as the engineer responsible for all the machining operations.

Your friend knows that you have taken ISEN 281 and often seeks your advice.

(1) For grinding very hard steel parts, which type of grinding wheels should be used?

(A) CBN. (B) Diamond

(A) CBN.

In order to reduce surface roughness (i.e. to make the surface smoother), which grinding wheel should be used?

(A) The wheel with mesh size of #300. (B) the wheel with mesh size of #800.

(B) the wheel with mesh size of #800.

Both USM and RUM are ________ Non-Traditional Machining processes.

(A) mechanical (B) chemical (C) thermal

(A) mechanical

In _______, an abrasive slurry is used. (A) USM (B) RUM

(A) USM

In _______, a fix-abrasive tool is used. (A) USM (B) RUM

(B) RUM

In _______, non circular holes (and cavities) cannot be machined. (A) USM (B) RUM

(B) RUM

In _______, either the tool or the workpiece vibrates at high frequency.

(A) USM (B) RUM (C) both USM and RU

(C) both USM and RU

EDM (Electrical Discharge Machining) has several benefits. Which one of the following is NOT among these benefits?

(A) No cutting forces. (B) Burr-free edges.

(C) The tool never wears. (D) Intricate (complex) details can be cut.

(C) The tool never wears.

Which one of the following is NOT among the limitations of EDM?

(A) Low material removal rate. (B) Can cut only one hole at a time.

(C) Long time to prepare tools. (D) Workpiece material must be conductive.

(B) Can cut only one hole at a time.

In EDM, as on-time increases, the surface generated becomes ________.

(A) rougher (B) finer

(A) rougher

In EDM, as on-time increases, the overcut ____________.

(A) increases (B) decreases

(A) increases

In wire-EDM, _______________________

(A) wire products are produced. (B) a moving wire is used as the tool.

(B) a moving wire is used as the tool.

1-4) On a machining center, parts (with the same design and material) have been machined satisfactorily for a long time.

However, something went wrong today. The cutting forces have exceeded the limit when milling a surface and the machine has automatically shut itself down. This is a serious problem and the plant manager has come to you for your

advice. From what you have learned from ISEN 281, you will tell the plant manager that several things have to be examined to find the causes for the exceedingly high cutting forces.

(T1) Only two computer control programs are used on this machine. The only difference between the two programs is the depth of cut; and most of time the program with the larger depth of cut is used. Should the computer program be

checked to see if the wrong program was used today?

(A) Should. (B) No need

(B) No need

1-4) On a machining center, parts (with the same design and material) have been machined satisfactorily for a long time.

However, something went wrong today. The cutting forces have exceeded the limit when milling a surface and the machine has automatically shut itself down. This is a serious problem and the plant manager has come to you for your

advice. From what you have learned from ISEN 281, you will tell the plant manager that several things have to be examined to find the causes for the exceedingly high cutting forces.

Tempering is always used to heat-treat the parts before they are machined on this machining center. Should the

plant manager check whether the tempering step was accidentally skipped for today’s parts?

(A) Should. (B) No need

(B) No need

1-4) On a machining center, parts (with the same design and material) have been machined satisfactorily for a long time.

However, something went wrong today. The cutting forces have exceeded the limit when milling a surface and the machine has automatically shut itself down. This is a serious problem and the plant manager has come to you for your

advice. From what you have learned from ISEN 281, you will tell the plant manager that several things have to be examined to find the causes for the exceedingly high cutting forces.

Cutting fluid is always used for the milling operation. Should the plant manager check if today’s coolant flow rate

was lower than normal?

(A) Should. (B) No need.

(A) Should.

Only two milling cutters are used on this machine. The only difference between the two tools is the rake angle; and

most of time the tool with the smaller rake angle is used. Should the tool be checked to see if the wrong tool was used

today?

(A) Should. (B) No need.

(A) Should.